Science That is
Not So Scientific

Reviewed by Cornelius HunterAuthor of: Darwins God: Evolution and the Problem of Evil

Evolution: The Triumph of an Idea, by Carl Zimmer
HarperCollins, NY, 2001.

A good way to learn science is to study the history behind the science. Quantum
mechanics doesnt make much sense until one understands the experiments
and ideas leading up to it. Likewise, understanding the cultural and historical
context of evolution helps one to understand Darwins theory itself.
Carl Zimmer is keenly aware of this. In his wonderfully written and illustrated
Evolution: The Triumph of an Idea, Zimmer describes the world of the
scientists who developed the theory in a way that helps the reader understand
the science itself.

In the tradition of Maitland Edeys and Donald Johansons Blueprints:
Solving the Mystery of Evolution and the venerable Time-Life science volumes
(where Edey served for many years) Zimmers work is at the high end of
the popular science literature. Blueprints had more detail than a typical
Time-Life volume but it lacked the vivid illustrations. Zimmers Evolution,
the companion book to the generously funded PBS series of the same name, has
both. And Zimmer has found a way to write a long book on science that doesnt
lose the readers interest.

An important drawback of this genre, however, is its tendency toward the
superficial. The unavoidable details that complicate science are often ignored
so as not to confuse the message. Pedagogy is sometimes placed above veracity.
This same criticism holds for the PBS television series as well, where the
viewer was given simplified messages that sometimes misrepresented the state
of the theory. It would not be inaccurate, nor I think offensive, to say that
the Evolution Project is geared not so much at teaching evolution but at promoting
evolution.

As I shall document below, Zimmer consistently tells an overly optimistic
story. As a popular tome supporting the pro-evolution perspective, Zimmers
work is excellentperhaps the best there is right now. But like the theory
it defends, Zimmers work should not be confused with an even-handed,
neutral assessment of the facts. As with the television series, the production
is excellent but the content is committed to a particular view.

Missed opportunities

Darwinism is a truly fascinating story within the history of thought, and
each time Zimmer oversimplifies he misses another opportunity to tell that
story. For example, in formulating his theory, Darwin grappled with the problem
of how the blind action of evolution could ever create anything so complicated
as life. He took as his example the eye which Darwin admitted made his theory
appear to be absurd in the highest possible degree. Darwin then
supplied two arguments against such a conclusion. What is interesting about
the whole passage is that both arguments are blatantly nonscientific.

The problem of complexity

The first argument is an old debating trick that requires the opponent to
prove the impossible. If it could be demonstrated, wrote Darwin,
that any complex organ existed, which could not possibly have been formed
by numerous, successive, slight modifications, my theory would absolutely
break down. But I can find out no such case. Here Darwin called for
a universal negative to be provedhardly a scientific criterion.

Darwins second argument against the problem of complexity was even
more nonscientific. He admitted that the eye, like the telescope, appeared
to be designed, but he warned against this conclusion, for we should not assume
that the Creator works by intellectual powers like those of man. Darwin
was appealing to certain ideas about God that have traditionally been popular.
The argument depends on ones religious beliefs and cannot be judged
by science.

Zimmer misses a great opportunity to reveal the subtleties of evolution when
he discusses Darwins handling of the problem of complexity. Zimmer ignores
these arguments and instead presents a few of Darwins hypothetical scenarios,
such as how bats might have evolved from squirrels. It is nothing more than
speculation, but Zimmer leaves the reader with the impression that this difficult
problem has been practically resolved. [p. 49]

The immune system

Unfortunately Zimmer misses many such opportunities. There is the immune
system and how it illustrates conditions under which natural selection can
work. A challenge for Darwinism is that the design space of life is enormous.
How is one species to evolve into the next when there are so many dead
ends in the way? Random biological variation provides a sampling of
the design space from which evolution is supposed to select, but each sample
requires a life span of time. In other words, each individual in a population
is an evolutionary experiment, but the experiment can take a long time. Furthermore,
most of these experiments are not very meaningful, as most individuals have
a complement of genes that does not stray very far in the design space.

The immune system, on the other hand, explores a smaller design space using
far more efficient sampling. Experiments are carried out rapidly and they
tend to be more evenly spread out in the design space. The immune system makes
for an interesting analogy with Darwinism. Clearly, it illustrates how natural
selection can work, but the process is very different from Darwins proposed
process. Zimmer leaves out these complicating issues and instead gives the
impression that the immune system serves as evidence for evolution. [p. 92
ff]

Evolutionary computing

In a similar fashion Zimmer enlists evolutionary computing as further justification
for Darwinism. Evolutionary computing is a fascinating field that has high
potential in a variety of applications. But it requires tremendous effort
from computer scientists as they build the controlled conditions that produce
meaningful results. It is especially weak as evidence for Darwinism because
biologys real-world problems are easily (and necessarily) omitted in
the antiseptic world of computer simulation. Furthermore, the results never
come easily but require the determined work of computer scientists who carefully
design their experiments to achieve the desired results.

Zimmer skips these complicating details. In one of his examples, a scientist
used evolutionary computing to design an electronic circuit. Zimmer incorrectly
concludes that the good result came without any direction from
the scientist. Without the scientists careful design, the simulation
would never have produced the good result. [p. 96]

Origin of life

Zimmer states that scientists have found compelling evidence that life
could have evolved into a DNA-based microbe in a series of steps. This
is overly optimistic to the point of misrepresenting the state of the research.
Origin of life research is nowhere near to such an achievement. In fact Zimmers
description of the research is liberally sprinkled with qualifiers such as
might have, may have, and scientists suspect.

Origin of life research is an area of research that is highly speculative
and lacks strong motivating evidence. For many, it seems clear that the research
is motivated by the assumption that evolution is true and that the results
must be interpreted as such. In other words, researchers will never conclude
against a natural origin of life and results will always be given a pro-evolution
spin. This is an interesting story that forces one to think hard about the
limits of science, but none of this comes through in Zimmers simplified
account.

Zimmer writes that the raw materials required for the origin of life could
have come from space. Meteorites, comets, and interplanetary dust,
he explains, could have seeded the planet with components for crucial
parts of the cell. But only a few of the many chemicals used in the
cell would have been available and only in low concentrations. For this problem,
Zimmer explains that the chemicals might have been concentrated in raindrops
or the spray of ocean waves.

If we doubt this particular scenario, Zimmer explains that other scientists
suspect that life began at the midocean ridges. And yet another
take on the problem is the possibility of cycles of chemical reactions that
scientists suspect could sustain themselves. There may have been many
separate chemical cycles at work on the early Earth The most efficient
cycle would have outstripped the less efficient ones. Before biological
evolution, Zimmer easily concludes, there was chemical evolution.

Anyone who has read this literature knows how extremely hypothetical it is
and how far researchers are from producing anything resembling the cell. None
of this remotely supports Zimmers lofty claim that scientists have
found compelling evidence that life could have evolved into a DNA-based microbe
in a series of steps. [pp. 104 ff.]

The tree of life

Zimmer discusses evolutions tree of life and its proposed universal
common ancestor. In the early days of microbiology all cells were categorized
into one of two groups. There were the larger, more complicated cells called
eukaryotes and the smaller, simpler ones called prokaryotes. It seemed obvious
to evolutionists that the prokaryotes arose first in the history of life and
that the eukaryotes appeared later as evolutionary descendents of the prokaryotes.

But in the 1970s researchers first began comparing the genetic material of
prokaryotes and eukaryotes in detail. They made two interesting discoveries:
first, that there appeared to be a third cell type, and second, that the three
types (called eukaryotes, bacteria and archaea) were too different to have
evolved from each other. In other words, though the cell types were similar
in many ways, no direct evolutionary relationships could exist between them.

Did life arise three times to produce the three similar cell types? Evolutionists
said No. They postulated that the three lineages must have evolved
from a single progenitor. Having a single progenitor evolve in three different
directions would explain the substantial similarities of the cell types without
requiring any direct evolutionary relationship between them.

The problem with this explanation is that no fossil or living examples of
a potential progenitor have been found. The postulate that it existed and
evolved to produce the three different lineages is speculative and is mainly
supported by the assumption that evolution is true.

The next step was to piece together what the progenitor would have looked
like by comparing the genetic differences and similarities of the three cell
types. But the task became confusing when it was discovered that the genes
of the cell types varied widely. No clear picture of a simple progenitor emerged;
instead, the only solution seemed to be a super progenitor that already had
most of the highly complex traits found in each of the three types.

The super progenitor would have been as complex as modern cells yet somehow
would have arisen in a short time. Again, evolutionists have proposed a speculative
scheme to solve the problem. Perhaps the distribution of genes in the three
cell types could have resulted if the progenitor was so rudimentary that genetic
material was readily exchanged between cells in the same population. The process
is roughly akin to what is known as lateral gene transfer in modern
cells but on a grander scale. The result would be that evolution would occur
more between neighbors than between parents and offspring.

But this scheme is even more speculative than the preceding one. Not only
is there no evidence for such an evolutionary process, but there is a wealth
of missing detail. Zimmers version of the story omits these difficulties.
He tells the story with plenty of details and he admits that questions remain,
but his message, that yet another area of research confirms evolution, is
simply not justified. [pp. 103 ff.]

Small-scale evolution

Small-scale evolution, such as insects gaining resistance to pesticides,
is hard evidence. Evolutionists use it as one of the major pillars of evidence
supporting Darwinism. They often go so far as to say that it demonstrates
that their theory is a fact. But there are several problems with this evidence
that are consistently ignored. There is the unresolved question of whether
small-scale evolution can extrapolate to the sorts of large-scale evolution
Darwinism requires. Evolutionists assume that small-scale evolution is unbounded,
but there is no scientific evidence for this.

Then there is the existence problem. Evolution relies on the preexistence
of biological variation without understanding from where it came. Small-scale
evolution is a result of a reproduction process that includes exquisite and
complicated molecular machinations. Evolutions explanation for how it
created this process is speculative, yet it relies on this process. We are
to believe that evolution created the very process that enables further evolution.

These are interesting questions, but Zimmer skips them. Instead, he discusses
examples of species undergoing minor variation that tell us very little about
the extrapolation and existence problems. For example, Zimmer explains that
climate variations on the Galapagos Islands have caused variations in the
beaks of finches. After a series of climate variations researchers found no
overall trend in the beak size. Though such short-term climate fluctuations
have no overall effect, Zimmer tells the reader that significant evolutionary
change would be possible given different conditions. But there is no evidence
for Zimmers claim, aside from the assumption that evolution is true.
[p. 87-8]

Large-scale evolution

Somehow evolution must create big changes as well as small changes. For the
big changes, Zimmer explains how easily genes can be duplicated and subsequently
mutated to take on new function. [p. 111] However when explaining the advantages
of sexual reproduction, Zimmer explains how difficult it is for mutations
to produce a good gene. [p. 232-3] And when explaining how evolution can result
in quirky designs, Zimmer states that evolution can only tinker with
what the history of life has already created. [p. 118]

Darwinism is a very flexible theory and it is tempting for evolutionists
to shape the idea to fit the needs of the moment. On the one hand, evolution
has created the incredible diversity and complexity of life; on the other
hand, it is constrained and has only limited creative powers. Evolution can
produce large-scale changes in every direction, resulting in a fantastic variety
of creatures and optimal designs. But evolution is also constrained, resulting
in the quirks of nature. For every occasion Darwinism has an explanation.

Zimmer also justifies the idea of large-scale evolution by claiming that
the observed rates of small-scale evolution are greater than the required
rates of large-scale evolution. Traits in guppies, such as their growth patterns,
were found to change when the guppies were placed in a new environment. The
guppies, of course, were still guppies, but Zimmer argues that the rate of
change observed is sufficient to account for changes in the fossil record.
But there is no justification for assuming that such small-scale changes fall
into the same category as large-scale changes. And Zimmer does not mention
that there is no evidence for the underlying assumption that small-scale change
is unbounded. Instead, he makes the unjustified conclusion that if you
accept microevolution, you get macroevolution for free. [p. 325]

Evolutionists have traditionally argued for large-scale evolution by presenting
neat, clean evolutionary diagrams, and Zimmer does just that on page 138.
The diagram illustrates an evolutionary progression starting with a four-legged
carnivore and ending with an ancient whale. In the text Zimmer gives more
details about the actual fossil data but, as they say, a picture is worth
a thousand words. The diagram conveys a simplified and carefully tailored
version of the true fossil data. It draws attention away from the significant
problems with the idea of large-scale evolutionary change.

Just add water

Darwinism maintains that life comes about on its own. If we are to accept
this proposition we must believe that the process is, for the most part, not
unlikely. Darwinism needs the unguided creation of life to be an ordinary
process rather than a succession of miracles. A good motto for evolution would
be: Life Happens.

Throughout the book Zimmer advocates this view of evolution. Regarding the
creation of eyes, Zimmer writes, Some crustaceans have eyes that consist
of little more than a layer of pigment coated by a membrane. Over time, this
membrane could separate from the pigment and begin to act like a crude lens.
With small alterations, such an eye could turn into the precise telescopes
that birds and mammals use. [p. 49]

And this would include the amazing double eyes that fish use to look through
air and water simultaneously. As Zimmer explains: Once the vertebrate
eye had evolved, complete with lens, jelly, and backward retina, many lineages
evolved new versions that work better in their own environment. For example,
three different lineages of fishes have each evolved double eyes. Their eyes
have two pairs of lenses rather than one; when these fishes float at the waters
surface, one pair of eyes gazes up into the air, while the other looks down
into the water. The upward-pointing eyes are shaped to focus light as it passes
through air, while the other pair is designed to handle the optics of water.
[p. 131]

There are many other amazing eye designs that Zimmer would presumably have
no trouble ascribing to the unguided process of evolution. Once you have accepted
the notion that the most complicated things we know of arose by the simplest
of means, then just about anything can be explained.

Regarding the origin of mitochondria, the powerhouse within cells, Zimmer
describes the idea that the ancestral mitochondria was a free-living microbe
that merged with a larger cell. It has been suggested, writes Zimmer, that
protomitochondria may have hung around early eukaryotes to feed on their wastes,
and the eukaryoteswhich could not use oxygen for their metabolismcame
to rely in turn on the wastes of the oxygen-breathing protomitochondria. Eventually
the two species and the exchanges between them began to take place within
a single cell. [p. 114]

There is a quality of credulity in these accounts that makes them difficult
to take seriously. It seems that evolution can achieve just about anything
we can imagine. Regarding the Cambrian explosion, where so many new species
rapidly appeared, Zimmer explains that Because animals already had their
complex genetic circuits in place, they could respond to this evolutionary
pressure by flowering into all the forms of the Cambrian Explosion
Once algae eaters began to thrive, they spurred the appearance of large, fast-swimming
predators, which in turn could have been devoured by large predators still.
[p. 127]

Likewise, Zimmer explains how blood clotting molecules came about. Imagine
an early vertebrate that lacked any clotting factor whatsoever Now
imagine that the gene for a slicing enzyme was duplicated. The extra copy
evolved into a simple clotting factor made only in the bloodstream. It would
be activated in a wound and slice apart proteins in the blood, some of which
would turn out to be sticky. A clot would form, one that was superior to the
old kind. If this initial clotting factor was duplicated, the chain reaction
would double in length and become more sensitive. Add another factor, and
it gets more sensitive still. Gradually the entire clotting process could
have evolved this way. [p. 329]

Zimmer makes it appear all so easy. But these purported explanations of major
evolutionary leaps lack the detail necessary to make them convincing. In reading
through Zimmers accounts, the uncommitted reader is driven to suspect
that something more than scientific reasoning is at work. The speculation
is so rampant and contrary to the scientific method that one cannot help but
think that there are deep motives behind evolution.

What evolution really is

One of the favored evidences for evolution these days is the universal genetic
code, or DNA code for short. The DNA code is used to read the information
stored in the cells genetic library, and essentially the same code is
found in all species, from whales to oak trees to the bald eagle. Discovered
in the second half of the twentieth century, evolutionists triumphantly hail
the DNA code as a great confirmation of Darwins theory.

The DNA code

But we may ask: Why does the DNA code confirm Darwinism? The code and its
attendant molecular machinery reveal a profound level of complexity about
which Darwinism can only speculate. How could such a complex system have evolved?
A great variety of explanations of the codes supposed evolution are
currently under consideration. And they are filled with more speculation than
hard fact. Furthermore, evolution never predicted a universal code. In fact,
some evolutionists have expressed surprise that there arent multiple
codes in nature. Why arent different codes found among the species?
Darwinism would have no problem with such a finding. In fact variations in
the code have been discovered and they have not caused so much as a ripple
in the evolution camp.

The DNA code is not predicted nor required by evolution, nor can evolution
explain how it evolved with any level of detail or certainty. It would seem
that this hardly makes for good evidence. The reason evolutionists tout the
DNA code as evidence, however, has nothing to do with these issues. Darwinists
see the DNA code as evidence that all species are related under common ancestry,
regardless of how it evolved.

Of course, no one can deny that the DNA code reveals a relationship between
the species. It would be absurd to think it coincidentally arose in all those
different species. But there is a difference between relationship and common
ancestry. The key to understanding evolution is to understand the metaphysics
inherent in this and the other major pieces of evidence for evolution. When
evolutionists see a relationship, they explain it using common ancestry regardless
of the scientific evidence. The common ancestry explanation is taken as compelling
even in the most unlikely cases.

I discuss the source and rationale for this sort of thinking in Darwins
God. For now, suffice it to say that, in a subtle way, evolution relies
on a particular metaphysical view of nature, and there are examples aplenty
of this in Zimmers work.

Transplanted genes

In trying to rationalize the Cambrian explosion, Zimmer discusses genes that
control the development of the nervous system in a wide range of organisms,
including vertebrates and arthropods. The genes across this wide range of
species are very similar. In fact, a gene from a fly can be inserted into
a frog embryo and it will successfully do its job. Such similar genes,
Zimmer writes, doing such similar jobs must have a common ancestry.
[emphasis added] Zimmer gives no scientific rationale for his striking conclusion,
for there is none. The claim that similar genes must share a common ancestry
is simply not within the bounds of science. [p. 124]

The PBS Evolution series discusses another such gene-transplant experiment
and arrives at the same strong conclusion. Theres only one inescapable
conclusion, pronounces geneticist Sean Carroll, which is: If all
of these branches have these genes, then you have to go to the base of that,
which is the last common ancestor of all animals, and you deduce it must have
had these genes. But this is simply not true. Carrolls claim that
his interpretation is the only possible interpretation reveals the underlying
presupposition that similarity mandates common ancestry.

When discussing evolutions tree of life, Zimmer writes: All living
things share certain things in common. All of them, for example, carry their
genetic information as DNA and use RNA to turn them into proteins. The simplest
explanation for these universal properties is that all living species inherited
them from a common ancestor. How could this possibly be the simplest
explanation with, for example, the problems of complexity and large-scale
change discussed above? This explanation brings with it a multitude of scientific
difficulties, but it appears simple if you already believe that similarity
implies common ancestry. [p. 103]

Chimeric genes

When the DNA code and its associated molecular machinery were first discovered
it was thought that there was a one-to-one correspondence between genes and
gene products. A single gene, it was assumed, produced a single protein or
RNA molecule. This was a reasonable first guess, but in later years it was
discovered that a single gene could produce multiple products. Overlapping
and chimeric genes can produce different products when read in
different ways. As a simple example, the word evolution can also
be used to spell out the word love if only the first four letters
are read, and in the reverse direction.

As if the genetic code and associated molecular machinery were not complicated
enough, this additional level of complexity is yet another challenge for Darwinism.
We must not only believe that random variations are the source of the meaningful
information encoded on the DNA strand, but that those variations also produced
overlapping or chimeric genes and the capability to read them.

One interesting example of a chimeric gene involves an antifreeze glycoprotein
(AFGP). Antifreeze glycoproteins have been discovered in a variety of Arctic
and Antarctic fish. They bind to ice and thus keep the fish from freezing.
In the evolution lore this is an example of convergent evolution
because the antifreeze genes in Arctic and Antarctic fish must have evolved
independently. In this case common ancestry is impossible so similarity is
interpreted as convergent evolution.

AFGP is similar to another protein, a functionally unrelated protease. Furthermore,
the genes for AFGP and the protease have been discovered both separately and
together in a chimeric gene. Evolutionists claim that the existence of the
chimeric gene proves that AFGP and the protease have a common ancestry.

Zimmer explains this story, omitting the challenges discussed above. He gives
a just-so story of how the protease gene was duplicated and edited to produce
the chimeric gene and ultimately the AFGP gene. He concludes that the chimeric
gene is a remarkable confirmation of common ancestry. The science
may be lacking, but again similarity is assumed to confirm common ancestry.
[p. 327-8]

Fossil similarities

The examples so far have been in the area of molecular biology, but metaphysical
assumptions are at the foundation of all evolutionary thinking. Zimmer tells
of a mammal fossil uncovered in Pakistan. The creature, dubbed Pakicetus,
is intermediate between mesonychids and later whales, confirming that
Pakicetus was in fact a 50-million-year-old whale. [p. 137]

But this is not the case. Fossils give us an idea of what creatures
existed in the past, but they do not tell us how the creatures got
there. Fossils may suggest evolutionary relationships, but they do not confirm
such relationships. As one recent paleontology text put it, the observed
fossil pattern is invariably not compatible with a gradualistic evolutionary
process. There is either a problem with the fossil record or with the
idea that evolution is gradual. To make the data compatible with the theory
undiscovered fossil forms can be proposed, or unknown mechanisms
of evolution can be proposed. But neither of these ad hoc hypotheses
are known to be true or untrue. [T.S. Kemp, Fossils and Evolution,
Oxford University Press, 1999]

Regarding the Cambrian explosion Zimmer writes, paleontologists have
found fossils of multicellular animals as old as 575 million years, some of
which are clearly relatives of the groups that appeared during the Cambrian
explosion 40 million years later. The fossils Zimmer has in mind show
similarities, but his unqualified conclusion that they are clearly relatives
goes beyond the data. [p. 324]

What is important here is to understand the nature of these claims. In these
various examples Zimmer is not just suggesting possible explanations for the
data. Nor can we say that he is merely making provisional claims. In this
popular work intended for the non expert, Zimmer is making metaphysical claims
under the banner of science.

Bad design

Another important evidence for evolutionists are the examples of confusing
design in nature. Darwin had many such examples and he used them to argue
that whereas a blind, undirected process such as evolution would be expected
to foul up once in awhile, a Creator would never produce less than perfect
designs. Darwins evolution did not explicitly predict such designs,
but the theory could accommodate them. The strength of the argument is in
its refutation of divine creation. It continues to be an immensely popular
argument among evolutionists, and in recent years has been directed against
the vertebrate eye. Zimmer approvingly quotes an evolutionists who calls it
stupidly designed. [p. 129]

Darwin struggled to explain how his process could produce the complexity
of the eye, but now evolutionists have defused the problem. Evolution may
not be able to explain how the eye could have evolved in any detailed sense,
but evolution seems to be the only alternative. Of course, this argument relies
on notions about the Creator and creation that are not open to scientific
debate.

The religion behind evolution

When Zimmer writes that similar genes must have a common ancestry,
and Carroll says that common ancestry is the inescapable conclusion,
they are relying on nonscientific, religious assumptions that are at the heart
of evolution. I discuss this at length in Darwins God. The influence
of religion in Darwinism is profound but subtle. Unlike Darwins theory
which states that many species arise from one, Darwinism is a single idea
that arose from many. One cannot simply point to a single motivating metaphysic
behind Darwinism. Neither Greek philosophy nor Enlightenment theology nor
Deism nor liberalism, for example, can alone explain Darwinism.

Two important influences are Gnosticism and natural theology. Darwinisms
debt to these two traditions is obvious, but they are quite different and
this makes for a complex story. In any case, what is most important to understand
is that the evolution-creation controversy has been misunderstood as science
versus religionit is really religion versus religion.

Instead of unwrapping the evolution story and clarifying the myths that have
grown up around it, Zimmers work only reinforces those myths. Evolution:
The Triumph of an Idea is of high quality volume but it adds little in
the way of a fresh understanding to this complex story. In promoting evolution,
Zimmer has not captured the essence of this important subject.